diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/parisc/math-emu/sfrem.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/parisc/math-emu/sfrem.c')
-rw-r--r-- | arch/parisc/math-emu/sfrem.c | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/sfrem.c b/arch/parisc/math-emu/sfrem.c new file mode 100644 index 000000000000..3a1b7a34d87a --- /dev/null +++ b/arch/parisc/math-emu/sfrem.c | |||
@@ -0,0 +1,290 @@ | |||
1 | /* | ||
2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) | ||
3 | * | ||
4 | * Floating-point emulation code | ||
5 | * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2, or (at your option) | ||
10 | * any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License | ||
18 | * along with this program; if not, write to the Free Software | ||
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | */ | ||
21 | /* | ||
22 | * BEGIN_DESC | ||
23 | * | ||
24 | * File: | ||
25 | * @(#) pa/spmath/sfrem.c $Revision: 1.1 $ | ||
26 | * | ||
27 | * Purpose: | ||
28 | * Single Precision Floating-point Remainder | ||
29 | * | ||
30 | * External Interfaces: | ||
31 | * sgl_frem(srcptr1,srcptr2,dstptr,status) | ||
32 | * | ||
33 | * Internal Interfaces: | ||
34 | * | ||
35 | * Theory: | ||
36 | * <<please update with a overview of the operation of this file>> | ||
37 | * | ||
38 | * END_DESC | ||
39 | */ | ||
40 | |||
41 | |||
42 | |||
43 | #include "float.h" | ||
44 | #include "sgl_float.h" | ||
45 | |||
46 | /* | ||
47 | * Single Precision Floating-point Remainder | ||
48 | */ | ||
49 | |||
50 | int | ||
51 | sgl_frem (sgl_floating_point * srcptr1, sgl_floating_point * srcptr2, | ||
52 | sgl_floating_point * dstptr, unsigned int *status) | ||
53 | { | ||
54 | register unsigned int opnd1, opnd2, result; | ||
55 | register int opnd1_exponent, opnd2_exponent, dest_exponent, stepcount; | ||
56 | register boolean roundup = FALSE; | ||
57 | |||
58 | opnd1 = *srcptr1; | ||
59 | opnd2 = *srcptr2; | ||
60 | /* | ||
61 | * check first operand for NaN's or infinity | ||
62 | */ | ||
63 | if ((opnd1_exponent = Sgl_exponent(opnd1)) == SGL_INFINITY_EXPONENT) { | ||
64 | if (Sgl_iszero_mantissa(opnd1)) { | ||
65 | if (Sgl_isnotnan(opnd2)) { | ||
66 | /* invalid since first operand is infinity */ | ||
67 | if (Is_invalidtrap_enabled()) | ||
68 | return(INVALIDEXCEPTION); | ||
69 | Set_invalidflag(); | ||
70 | Sgl_makequietnan(result); | ||
71 | *dstptr = result; | ||
72 | return(NOEXCEPTION); | ||
73 | } | ||
74 | } | ||
75 | else { | ||
76 | /* | ||
77 | * is NaN; signaling or quiet? | ||
78 | */ | ||
79 | if (Sgl_isone_signaling(opnd1)) { | ||
80 | /* trap if INVALIDTRAP enabled */ | ||
81 | if (Is_invalidtrap_enabled()) | ||
82 | return(INVALIDEXCEPTION); | ||
83 | /* make NaN quiet */ | ||
84 | Set_invalidflag(); | ||
85 | Sgl_set_quiet(opnd1); | ||
86 | } | ||
87 | /* | ||
88 | * is second operand a signaling NaN? | ||
89 | */ | ||
90 | else if (Sgl_is_signalingnan(opnd2)) { | ||
91 | /* trap if INVALIDTRAP enabled */ | ||
92 | if (Is_invalidtrap_enabled()) | ||
93 | return(INVALIDEXCEPTION); | ||
94 | /* make NaN quiet */ | ||
95 | Set_invalidflag(); | ||
96 | Sgl_set_quiet(opnd2); | ||
97 | *dstptr = opnd2; | ||
98 | return(NOEXCEPTION); | ||
99 | } | ||
100 | /* | ||
101 | * return quiet NaN | ||
102 | */ | ||
103 | *dstptr = opnd1; | ||
104 | return(NOEXCEPTION); | ||
105 | } | ||
106 | } | ||
107 | /* | ||
108 | * check second operand for NaN's or infinity | ||
109 | */ | ||
110 | if ((opnd2_exponent = Sgl_exponent(opnd2)) == SGL_INFINITY_EXPONENT) { | ||
111 | if (Sgl_iszero_mantissa(opnd2)) { | ||
112 | /* | ||
113 | * return first operand | ||
114 | */ | ||
115 | *dstptr = opnd1; | ||
116 | return(NOEXCEPTION); | ||
117 | } | ||
118 | /* | ||
119 | * is NaN; signaling or quiet? | ||
120 | */ | ||
121 | if (Sgl_isone_signaling(opnd2)) { | ||
122 | /* trap if INVALIDTRAP enabled */ | ||
123 | if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); | ||
124 | /* make NaN quiet */ | ||
125 | Set_invalidflag(); | ||
126 | Sgl_set_quiet(opnd2); | ||
127 | } | ||
128 | /* | ||
129 | * return quiet NaN | ||
130 | */ | ||
131 | *dstptr = opnd2; | ||
132 | return(NOEXCEPTION); | ||
133 | } | ||
134 | /* | ||
135 | * check second operand for zero | ||
136 | */ | ||
137 | if (Sgl_iszero_exponentmantissa(opnd2)) { | ||
138 | /* invalid since second operand is zero */ | ||
139 | if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); | ||
140 | Set_invalidflag(); | ||
141 | Sgl_makequietnan(result); | ||
142 | *dstptr = result; | ||
143 | return(NOEXCEPTION); | ||
144 | } | ||
145 | |||
146 | /* | ||
147 | * get sign of result | ||
148 | */ | ||
149 | result = opnd1; | ||
150 | |||
151 | /* | ||
152 | * check for denormalized operands | ||
153 | */ | ||
154 | if (opnd1_exponent == 0) { | ||
155 | /* check for zero */ | ||
156 | if (Sgl_iszero_mantissa(opnd1)) { | ||
157 | *dstptr = opnd1; | ||
158 | return(NOEXCEPTION); | ||
159 | } | ||
160 | /* normalize, then continue */ | ||
161 | opnd1_exponent = 1; | ||
162 | Sgl_normalize(opnd1,opnd1_exponent); | ||
163 | } | ||
164 | else { | ||
165 | Sgl_clear_signexponent_set_hidden(opnd1); | ||
166 | } | ||
167 | if (opnd2_exponent == 0) { | ||
168 | /* normalize, then continue */ | ||
169 | opnd2_exponent = 1; | ||
170 | Sgl_normalize(opnd2,opnd2_exponent); | ||
171 | } | ||
172 | else { | ||
173 | Sgl_clear_signexponent_set_hidden(opnd2); | ||
174 | } | ||
175 | |||
176 | /* find result exponent and divide step loop count */ | ||
177 | dest_exponent = opnd2_exponent - 1; | ||
178 | stepcount = opnd1_exponent - opnd2_exponent; | ||
179 | |||
180 | /* | ||
181 | * check for opnd1/opnd2 < 1 | ||
182 | */ | ||
183 | if (stepcount < 0) { | ||
184 | /* | ||
185 | * check for opnd1/opnd2 > 1/2 | ||
186 | * | ||
187 | * In this case n will round to 1, so | ||
188 | * r = opnd1 - opnd2 | ||
189 | */ | ||
190 | if (stepcount == -1 && Sgl_isgreaterthan(opnd1,opnd2)) { | ||
191 | Sgl_all(result) = ~Sgl_all(result); /* set sign */ | ||
192 | /* align opnd2 with opnd1 */ | ||
193 | Sgl_leftshiftby1(opnd2); | ||
194 | Sgl_subtract(opnd2,opnd1,opnd2); | ||
195 | /* now normalize */ | ||
196 | while (Sgl_iszero_hidden(opnd2)) { | ||
197 | Sgl_leftshiftby1(opnd2); | ||
198 | dest_exponent--; | ||
199 | } | ||
200 | Sgl_set_exponentmantissa(result,opnd2); | ||
201 | goto testforunderflow; | ||
202 | } | ||
203 | /* | ||
204 | * opnd1/opnd2 <= 1/2 | ||
205 | * | ||
206 | * In this case n will round to zero, so | ||
207 | * r = opnd1 | ||
208 | */ | ||
209 | Sgl_set_exponentmantissa(result,opnd1); | ||
210 | dest_exponent = opnd1_exponent; | ||
211 | goto testforunderflow; | ||
212 | } | ||
213 | |||
214 | /* | ||
215 | * Generate result | ||
216 | * | ||
217 | * Do iterative subtract until remainder is less than operand 2. | ||
218 | */ | ||
219 | while (stepcount-- > 0 && Sgl_all(opnd1)) { | ||
220 | if (Sgl_isnotlessthan(opnd1,opnd2)) | ||
221 | Sgl_subtract(opnd1,opnd2,opnd1); | ||
222 | Sgl_leftshiftby1(opnd1); | ||
223 | } | ||
224 | /* | ||
225 | * Do last subtract, then determine which way to round if remainder | ||
226 | * is exactly 1/2 of opnd2 | ||
227 | */ | ||
228 | if (Sgl_isnotlessthan(opnd1,opnd2)) { | ||
229 | Sgl_subtract(opnd1,opnd2,opnd1); | ||
230 | roundup = TRUE; | ||
231 | } | ||
232 | if (stepcount > 0 || Sgl_iszero(opnd1)) { | ||
233 | /* division is exact, remainder is zero */ | ||
234 | Sgl_setzero_exponentmantissa(result); | ||
235 | *dstptr = result; | ||
236 | return(NOEXCEPTION); | ||
237 | } | ||
238 | |||
239 | /* | ||
240 | * Check for cases where opnd1/opnd2 < n | ||
241 | * | ||
242 | * In this case the result's sign will be opposite that of | ||
243 | * opnd1. The mantissa also needs some correction. | ||
244 | */ | ||
245 | Sgl_leftshiftby1(opnd1); | ||
246 | if (Sgl_isgreaterthan(opnd1,opnd2)) { | ||
247 | Sgl_invert_sign(result); | ||
248 | Sgl_subtract((opnd2<<1),opnd1,opnd1); | ||
249 | } | ||
250 | /* check for remainder being exactly 1/2 of opnd2 */ | ||
251 | else if (Sgl_isequal(opnd1,opnd2) && roundup) { | ||
252 | Sgl_invert_sign(result); | ||
253 | } | ||
254 | |||
255 | /* normalize result's mantissa */ | ||
256 | while (Sgl_iszero_hidden(opnd1)) { | ||
257 | dest_exponent--; | ||
258 | Sgl_leftshiftby1(opnd1); | ||
259 | } | ||
260 | Sgl_set_exponentmantissa(result,opnd1); | ||
261 | |||
262 | /* | ||
263 | * Test for underflow | ||
264 | */ | ||
265 | testforunderflow: | ||
266 | if (dest_exponent <= 0) { | ||
267 | /* trap if UNDERFLOWTRAP enabled */ | ||
268 | if (Is_underflowtrap_enabled()) { | ||
269 | /* | ||
270 | * Adjust bias of result | ||
271 | */ | ||
272 | Sgl_setwrapped_exponent(result,dest_exponent,unfl); | ||
273 | *dstptr = result; | ||
274 | /* frem is always exact */ | ||
275 | return(UNDERFLOWEXCEPTION); | ||
276 | } | ||
277 | /* | ||
278 | * denormalize result or set to signed zero | ||
279 | */ | ||
280 | if (dest_exponent >= (1 - SGL_P)) { | ||
281 | Sgl_rightshift_exponentmantissa(result,1-dest_exponent); | ||
282 | } | ||
283 | else { | ||
284 | Sgl_setzero_exponentmantissa(result); | ||
285 | } | ||
286 | } | ||
287 | else Sgl_set_exponent(result,dest_exponent); | ||
288 | *dstptr = result; | ||
289 | return(NOEXCEPTION); | ||
290 | } | ||